What is the difference between the 5kHz and 100kHz frequencies in electrical fast transient burst experiments

In the standard of IEC 61000-4-4, the electrical fast transient burst test specifies that two different frequencies are tested using 5KHz and 100KHz, respectively. What are the main differences between 5KHz and 100KHz?

From a frequency perspective, the 100KHz frequency pulse group interference is more severe, and the tested product is relatively more prone to problems. From the actual situation, 100 kHz is closer to the actual situation.

Due to the actual value of the repetition frequency of a single pulse of the electrical fast transient pulse group impulse from 10kHz to 1MHz, extensive investigation results indicate that it is difficult for generators with fixed spark gaps to reproduce this relatively high repetition frequency, so the standard specifies low-frequency and representative special pulses.

Therefore, in the process of formulating pulse group test standards, the pulse frequencies of 2.5kHz and 5kHz are inevitable with the update of pulse forming devices, especially the selection of high-speed high-voltage electronic switches, which increases the pulse frequency to 5kHz and 100kHz, making the pulse group immunity test more practical.

The latest version of GB17626.4-2018 Electrical Fast Transient Pulse Group Standard also states: Traditionally, 5kHz, however, 100kHz is closer to practical application!